Chevrolet K5 Blazer
See also Chevrolet Blazer (disambiguation)
|Assembly||Janesville, Wisconsin, USA|
|Successor||Chevrolet Tahoe |
|Body style(s)||2-door SUV|
|Layout||Front engine, rear-wheel drive / four-wheel drive|
The K5 Blazer was the smallest full size SUV version of the General Motors C/K Trucks family. Introduced to the Chevrolet line in 1969, the full-size Blazer was replaced in 1995 by the Chevrolet Tahoe. In 1970, GMC introduced its own model of the truck, called the Jimmy, which lasted until the 1992 GMC Yukon. Both were based on the short wheelbase trucks and were available with either rear-wheel drive or four-wheel drive. The Blazer's long wheelbase relative (with an integrated rear body, and doors for 2nd row passengers) is known as the Chevrolet Suburban.
The K5 Blazer and Jimmy had "full convertible" removable tops until 1976. In 1976 GM introduced a half-cab design that was less prone to leaks and slightly safer in a roll-over. These half cabs are convertible starting at a few inches behind the driver/passenger doors all the way back to the tailgate. In 1992 the Blazer was redesigned completely and no longer had a removable top.
Smaller models, the S-10 Blazer and S-15 Jimmy, were introduced alongside these trucks in 1983. The original Blazer and Jimmy remained in production until 1991; 1992 saw the introduction of a new K1500 Blazer (and the rebadged GMC Yukon) on the GMT400 platform. After 1994, the Blazer was renamed the Chevrolet Tahoe.
|Also called||GMC K5 Jimmy|
|Body style(s)||2-door SUV|
|Engine(s)||250 in³ I6 |
350 in³ V8
|Transmission(s)||3-speed TH-350 automatic |
3-speed manual4-speed manual
The original K5 was a short wheelbase truck. It was available in 1969 as 4-wheel drive only; in 1970, a two-wheel-drive model was offered. There were four choices for power plants: the 250 in straight-6, the 292 straight-6, the 307 V8, and the 350 V8.
The Blazer was designed and marketed to compete with International Harvester Scout and the Ford Bronco. Both of these were originally aimed at the short Jeep CJ series, which were much smaller than other trucks. The great innovation of the Blazer was to simply offer a shortened pickup truck, which both increased interior space, and lowered the cost of production with a shared platform. The Blazer quickly became popular. For the first time, it married the off-road capabilities of the Scout with the "luxury" features like air conditioning and automatic transmissions routinely available on pickup trucks. By 1970, the Blazer was already outselling both of its older rivals. Ford, Dodge, and even Jeep would counter with similar shortened pickups, with the Dodge Ramcharger and Jeep Cherokee.
The two-wheel drive version came with independent front suspension and rear trailing arms, both with coil springs. The four-wheel drive version had a solid front axle and used leaf springs front and rear. Both versions used drum brakes at all four corners until 1971, when the entire GM light truck line got standard front discs.
There was also a choice between a three-speed automatic transmission Turbo Hydromatic (TH350), a three-speed manual transmission, and a four-speed Saginaw Muncie (SM465) manual transmission. Two transfer cases were offered: the Dana 20, available only with the manual transmissions, or the NP-205, available with both types of transmissions.
- 250 in³ (4.1 L) I6 (1969-1984)
- 292 in³ (4.8 L) I6 (1970-1971)
- 307 in³ (5.0 L) V8 (1969-1973)
- 350 in³ (5.7 L) V8 (1969-1991)
- Dana 20 - gear driven part-time four-wheel drive
- NP-205 - gear driven part-time four-wheel drive
|Also called||GMC K5 Jimmy|
|Engine(s)||250 in³ I6 |
6.2 L Detroit Diesel V8
|Transmission(s)||4-speed SM465 manual |
|Wheelbase||106.5 in (2705 mm)|
|Length||184.8 in (4694 mm)|
|Width||79.6 in (2022 mm)|
|Height||73.8 in (1875 mm)|
|Fuel capacity||31 US gallons (117.3 L; 25.8 imp gal)|
Until 1976, the K5 had a removable convertible top. After this, a half-cab design was used until 1991.
Although the GMT400 platform was introduced in the spring of 1987 as a 1988 model, the K5 Blazer, Suburban, and crew-cab trucks retained the earlier platform until 1991. In 1989, the front grille was changed to resemble the squared-off ones used on the GMT400 series of pickups.
The K5 Blazer is very popular in the off-roading scene. It is a strong truck with the 350 V8 (which was the optional power plant), the gear driven NP-205 and ten and twelve bolt axles. It is very easy to upgrade this engine, because there are many companies with performance parts available. Later models produced after 1980 used the chain-driven NP208 transfer case, and the NP241 after 1988.
Since 1981 (in the wake of the 1973 Arab Oil Embargo and the 1979 energy crisis), Chevrolet and GMC used the smaller displacement 305s with a 9.2:1 compression ratio. These engines produced nearly as much torque as the 350, giving a similar driving feel. However, these power plants were underpowered and susceptible to detonation (engine knocking), especially with the electronic spark control module. To achieve the 9.2:1 compression ratio, the cylinder head chambers were smaller, measuring 54 cc instead of 60 cc. Despite a camshaft swap, some Blazer owners swapped out the 305s in favor of 350s, since the smaller displacement power plant was used in all Chevrolet/GMC pickups and passenger cars.
After 1987, when Throttle Body Injection was introduced in the truck engines, the 350 was made the standard power plant.
- 250 in³ (4.1 L) I6 (1973-1984)
- 305 in³ (5.0 L) V8 (1976-1987)
- 307 in³ (5.0 L) V8 (1973)
- 350 in³ (5.7 L) V8 (1973-1991)
- 400 in³ (6.6 L) V8 (1975-1980)
- 6.2 L Detroit Diesel (379 in³) V8 (1982-1991)
- Turbo Hydromatic TH-350 three-speed automatic (1973-1981)
- Turbo Hydromatic TH-400 three-speed automatic (1974-1979)
- 700R4 (4L60) four-speed overdrive automatic (1982-1991)
- Saginaw SM465 four-speed manual (1973-1991)
- Dana 20 - gear driven part-time four wheel drive (1973)
- NP-205 - gear driven part-time four wheel drive (1973-1980)
- NP-203 - chain driven full-time four wheel drive (1973-1979)
- NP-208 - chain driven part-time four wheel drive (1981-1988)
- NP-241 - chain driven part-time four wheel drive (1988-1991)
- Dana 44 - Front axle (1973-1977/78)
- GM Corporate 10 Bolt - Front axle (1977/78-1991)
- GM Corporate 12 Bolt - Rear axle (1973-1981)
- GM Corporate 10 Bolt - Rear axle (1982-1991)
|Also called||GMC Yukon|
|Engine(s)||350 in³ (5.7 L) L05 V8 |
395 in³ (6.5 L) Detroit Diesel V8
|Transmission(s)||4-speed 4L60E automatic |
|Wheelbase||111.5 in (2832 mm)|
|Length||187.7 in (4768 mm)|
|Width||76.4 in (1941 mm)|
|Height||71 in (1803 mm)|
|Fuel capacity||30 US gallons (113.6 L; 25.0 imp gal)|
The full-size Chevrolet Blazer was updated in 1992 on the new GMT400 platform and lasted through the 1994 model year. The GMC Jimmy moniker was dropped from the full size SUVs for 1992, and the GMC Yukon nameplate was introduced that year. The Blazer platform was known as GMT415, and the Yukon was GMT430.
The models were mostly identical to each other save for emblems and identification, grilles, and some trim packages, Cheyenne and Silverado for Chevy, SL and SLE for GMC. A Blazer Sport was offered with a flat graphite color applied to the lower areas of the vehicle and fender flares. A GMC Yukon GT was offered in a two-tone paint scheme early on with fender flares, it was then changed to a monochromatic appearance package later on.
These trucks had a slightly longer wheelbase than the previous models to improve drivability and towing, but there was no removable top offered, with a hatch and tailgate in the rear. Most were equipped with roof racks. The new frame was strengthened and an independent front suspension design was used. The 350 throttle-body injected V8 was carried over from the 1991 models. In 1993 an electronically controlled 4l60e transmission was introduced, darker tinted glass was used for the rear hatches. In 1994 the grille shell was updated and an LED third brake light added. A 6.5 liter turbo diesel was offered as well.
In 1995 the full-size Blazer was redesignated as the Chevy Tahoe to be sold along with it's new 4 door "shortened Suburban" counterpart, and the interior was redesigned with a new dashboard, seats, and door panels. The Yukon received the same treatment. In 1996, a new Vortec 5.7 liter 350 V8 was introduced to replace the old 350 throttle body injection engine, along with OBD-II diagnostics.
A Z71 off-road suspension RPO was offered on these trucks from 1992-1999 which consisted of larger 265/75/R15 tires, Bilstein shocks, skid plates, and some other beefed up items, just like the pickups had. Contrary to common belief, no 2 door Blazer, Yukon, or Tahoe ever left the factory with a Z71 decal on the side.
The 2-door Tahoe was in production up until 1999, the last model year for this 2-door SUV. The 2 door GMC Yukon on the GMT400 platform was produced until 1997.
Around 1981, a prototype K5 Blazer was used as a testbed for a military CUCV vehicle. Between 1983 and 1986, what is known as the M1009 CUCV was the production militarized version of the civilian K5. The only differences are the lack of an air conditioner and an additional leaf spring in the suspension. A majority of them are painted olive drab green or in the woodland camouflage pattern, though some vehicles that saw desert use were painted tan. All M1009s, including its derivatives, are powered with the 6.2 L Diesel power plant.
The M1009s have a split 24/12 volt electrical system. Most of the truck actually runs on 12 volts. It has two separate 12v alternators and batteries wired in series, only the glow plug system, the starter, and the jumper cable jack are wired to the 24 volt terminals. everything else in the truck runs on 12 volts. The glow plugs are actually 12 volt glow plugs with a resistor pack on the firewall to drop the 24v down to 12v. This resistor pack can be bypassed and the glow plugs run directly off of the 12v battery. If this is done and the 24v starter is replaced with a standard 12v starter the second alternator and battery are no longer needed. (If this is done then the military 24v slave adapter in the grille will need to be disconnected as well.)
Some decommissioned M1009s end up in law enforcement use (e.g. with the Los Angeles County Sheriff's Department) or sold through government auctions, but a handful are still in use by the National Guard.
Chevrolet, a division of General Motors, light truck timeline, United States market, 1950s–1970s — next »
|SUV||K5 Blazer||K5 Blazer|
|Advance Design||Task Force||C/K||C/K||C/K|
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|Coupe Utility||El Camino|